A counter-flow contactor provides efficient contact between opposing streams of material and is used to promote interaction between the two material streams. In many processes, the interaction can generate heat, causing the temperature of the materials to rise. For example, if the materials streams react chemically, then the heat of reaction can raise the temperature of the materials, sometimes causing the reaction to speed up and sometimes causing the reaction to slow down. In other process, the interaction can cause the adsorption of heat, causing the material stream temperature to decrease. For example, powdered materials can be dried by removing adsorbed water by contacting the powdered solid with hot, dry air. However, the evaporation of adsorbed water will cause the air temperature to decrease, limiting the effectiveness of the air in drying the solid. In these cases, there is a need to be able to continuously add or remove heat while these two counter flowing streams are interacting.
Relevant art: U.S. Pat. No. 4,588,024; U.S. Pat. No. 4,237,008; WO 2013094206.